High or low pressure control device

ABSTRACT

A pilot control for controlling the opening or closing of a controlled flow conduit in response to pressure variations in such flow conduit. Such pilot control including resilient biasing means urging a slide valve in one direction, said slide valve being urged in the opposite direction by fluid pressure, directly emitted from said controlled flow conduit. Such slide valve opens or closes communications between an outlet port and one of a plurality of inlet ports without seal means possessed by such slide valve crossing such ports.

United States Patent Taylor June 10, 1975 [541 HIGH ()R LOW PRESSURE CONTROL 3 l88 048 6/l965 Sutherland 4. 137/6255 X DEVICE 3.202.170 8/1965 1101mm 137/6255 x 3.260.504 7/1966 Mojonnier et al. [37/6255 X n n r: J eph y or. H IU Bri r ild. 3.461.911 8/1969 Janczur 137/6255 Houston. Tex. 7055 123 piledv Jam 1974 Primary Examiner-Henry T. Klinksiek Ark/me Age/11. or FirmRobcrt W. B. Dickerson [Zl] Appl. No.1 430.l62

Related US. Application Data 1 ABSTRACT 1113| Continuation of sew, No M1856. Dec. 7. 1971 A Pilot COMO Controlling the Opening of Closing abandoned. or" a controlled flow conduit in response to pressure variations in such flow conduit. Such pilot control in v US, Cl 251/14; 137/625 5[ cluding resilient biasing means urging a slide valve in [51] Int. Cl, Flfik 31/143 one direction, said slide valve being urged in thc oppo- |58 Field of Sear h H 137 458 491 625 25 27 site direction by fluid pressure, directly emitted from III/6356164 9 6254840; 251/14 said controlled flow conduit. Such slide valve opens or closes communications between an outlet port and [561 R feren e Cited one of a plurality of inlet ports without seal means UNITED STATES PATENTS possessed by such slide valve crossing such ports 3.044.492 7/1962 Peters et kll. 137/62566 9 l im 5 Dr ng Fig r s 1 HIGH OR LOW PRESSURE CONTROL DEVICE This application is a continuation in part of Ser. No. 3l2.856 filed on Dec. 7. I972, now abandoned.

BACKGROUND OF THE INVENTION Control means, or pressure sensing devices, such as pilot controls, have long been used to govern the opening and/or closing of a valve, which, in turn. governs the opening or closing of a flow conduit. An example of such a conduit may be the type used to transport petroleum products, natural gas or the like. In the event that pressure within such a flow conduit decreases below a desired level, such as on a break occurring, or above a desired level, such as on a blockage occuring, it may be advantageous or necessary to shut off flow through the conduit. Thus, control means have been developed which operate to cause such valve opening or closing as a function of the pressure within such a flow conduit. Examples of prior developments in this area are examplified by U.S. Pat. Nos. 3,043,33l; 3,083,726; 3,549,208 and 3,044,492; 3,587,647.

Such prior art devices have oftentimes been found objectionable because of rapid deterioration of seals and/or lack of sensitivity, i.e., failing to respond to relatively small pressure changes within the flow conduit. In effect, the pop point must be precise as well as consistant. While such difficulties have been overcome to some substantial degree, the resultant products have proved to be excessively expensive. It is to the solution of such problems that applicants invention is directed.

SUMMARY OF THE INVENTION The control device of this invention includes a valve housing, which housing includes a central body with plural entry ports and an exit port. Said body threadedly receives a cap at one end and a connector member at the other, said connector furnishing communication between a controlled flow conduit and the central bore of said central body. Within the bore of said body are positioned ball bearing means, hollow cylindrical adapters and spacers for receiving a slidable valve. Positioned within said cap, and urging said valve in the direction of said conduit is a resilient spring, the force of the pressure within said conduit urging said valve in the opposite direction. Communication paths for pilot fluid are established between each of said entry ports and said exit port through said valve. Either of said paths may be opened or closed by said valve, depending on its relative position. The control device is rendered extremely sensitive to pressure variations within said controlled conduit by virtue of (a) the provision of said bearing means, (b) low-friction seal members around said valve, and (c) very small travel of said valve, during which travel, no seal member crosses either an entry or exit port.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view illustrating a preferred embodiment of the present invention;

FIG. 2 is a partial sectional view illustrating an alternative modification of one end of the control device to provide a manual operation; and

FIGS. 3,4, and 5 are enlarged details showing discrete positions of the valve.

DESCRIPTION OF THE INVENTION Looking first at the embodiment of FIG. I, this control device includes a valve housing generally illustrated at 6. Said housing includes a central body portion 7, which in turn includes a longitudinally extending bore generally referred to by 9. Said bore may be said to join counterbores 9a and 56.

Inlet ports I0 and II, as well as outlet port 12, extend through the wall of body 7 and communicate with counterbore 9a. Hollow adapters 16,18,20 and 22 are positioned within counterbore portion 911, for purposes that will be described in greater detail hereinafter. Spacers may be inserted intermediate such adapters as needed. Said adapters each includes a longitudinal opening or passageway l7, 19, 21 and 23, respectively, which passageways are longitudinally aligned, and through which extends a slide valve referred to generally as 25. Said slide valve includes a plurality of members 27,28 and 29 which will be hereinafter described.

Valve housing body 7 threadedly and adjustably receives a cap 32. Interior of said cap there is positioned resilient biasing means in the form of a spring 35. One end of said spring abuts against end 33 of cap 32, and encircles a lug portion depending therefrom. The other end of spring 35 rests upon and abuts against an annular seat portion 36 of valve member 27, to bias or urge said slide valve 25, within passageways 17,19,21 and 23, in the direction of connector 6a and against the force of pressure stemming from a controlled conduit, said conduit not being shown. Said controlled conduit pressure acts on end of valve 25, in a direction opposite to spring 35, through bore or passageway 38 which extends longitudinally through connector member 6a. Said connector is seen to be threadedly attached to central body 7. In addition to furnishing fluid communication between a controlled conduit and the interior of the valve housing, connector 6a, by virtue of said threaded attachment to body 7, serves to fixedly position adapters 16,18,20 and 22 within the housing bore by compressing said adapters between the end of connector 6a and annular shoulder 40a, which shoulder joins counterbore 9a with bore 9.

Suitable seal means as illustrated at 41 are provided adapter 18, on each side of inlet port 11 to inhibit leakage of fluid. Suitable seal means 42 are also provided adapter 22, on each side of inlet port 10 to inhibit fluid leakage.

Member 29, which may be deemed a plunger, of slide valve 25, includes female portion 29a having bore 29b therein, which bore receives male portion 29c. Said male portion includes annular cutout 29d for receiving a dynamic seal comprising the low friction Teflon cup member 43. Thus, the fluid from the controlled conduit passing through passageway 38 is normally prevented from communicating with ports 10,11 or 12.

A vent 45 is provided through body 7, which communicates, by reason of enlargement 47 in counterbore 9a and lateral passageway 48 through adapter 16, with the longitudinal bore 17 through adapter 16 in which bore plunger 29 of the slide valve is received. Therefore, should any leakage of fluid from the controlled conduit around cup 43 occur, it will be vented to atmosphere rather than passing to the interior of the body portion to communicate with the pilot fluid flowing between the inlet and outlet ports.

The adapters l8 and 22 are each provided with an annular recess 50 on their outer periphery, which recesses may be screened to prevent the passage of impediments. Such recesses are adjacent the respective inlet ports 10,11. A lateral passage 53 through the walls of said adapters establishes fluid communication between said inlet ports and longitudinal passageways 19.23 of said adapters. Passages 53 enter longitudinal passageways 19,23 respectively between seal members 66 and 67 and between 68 and 69, said seal members to be described more fully hereinafter.

Each of adapters 18 and 22 is so formed as to include an annular shoulder 70, such facing shoulders being on opposite sides of outlet port 12. Adjacent each of such shoulders a taper 700 extends outwardly of the axial center of counterbore 9a to join the longitudinally extending inner wall of adapters 18 and 22. (See FIGS. 3-5) Such tapers face the adjacent seals 67 and 68.

Adapter 20 may also be deemed a spacer to position adapters 18 and 22 relative to the outlet port 12, so that this invention may be used as a high or low-pressure pilot control as will be described. If desired, a shim may be positioned intermediate members 18 and 20, or 20 and 22. Adapter or spacer 20 has enlarged diameter passageway or bore 21 relative to the diameters of passages 19 and 23 through adapters 18 and 22. Such enlarged bore permits the contacting of shoulders 70 by shoulders of annular enlarged portion 75 of valve member 28. Member 20 also includes an annular recess, which may also be screened, and a lateral passageway establishing communication between outlet port 12 and the longitudinal interior bore 21 of member 20.

Consider now the remaining components of slide valve 25. Element 27, on one end of which annular seat 36 is mounted, includes a stem portion extending from said seat to the other end of such element. Such extended stem is slidably carried in the bearing assembly referred to generally by 55. Such hearing may be seated within counterbore portion 56, and includes ball races 58 and 59. Suitable lock rings such as shown at 60 and 61 may position the bearing assembly within the coun terbore, and the stern relative to the bearing assembly.

The bearing portion described above performs a two fold purpose. First it tends to prevent buckling of the spring. This problem would cause a member, such as stem 27, to frictionally engage the side of a bore, and therefore not return all energy stored in the spring. Second, because of the extremely low friction losses between stem 27 and the balls, the possibility of ex trernely sensitive pop points is enhanced.

Member 28 of slide valve include seals 67,68 on either side of enlarged portion 75. These seals may be resilient O-rings of conventional material such as rubber or similar synthetic material. Member 28 also carries annular bearing and seal means 66 and 69 toward opposite ends thereof. Such means may include low friction bearing portions of material such as Teflon for slidable engagement with the interior walls of adapters l8 and 22. Positioned radially interior within the cutout portions, within which the low friction bearings are placed, may be conventional O-rings, for sealing purposes, out of engagement with such interior walls, i.e., such O-rings prevent fluid leakage around the radial interior of the low friction bearings. The unnumbered annular member shown in FIG. 1 above cup 43 (extending around portion 29a of plunger 29) may be a similar low friction bearing.

A vent 80 is provided toward the top of body 7, to vent any pilot fluid that may leak around the seal portion of means 69.

As illustrated in FIGS. 1,3,4 and 5, force from the fluid pressure within the controlled conduit, which may be attached to connector 6a would act through passageway 38 against the lower end 40 of plunger portion 29 of slide valve 25, urging said valve against the ad justable force of spring 35. Such force would tend to disengage member 67 from taper 700 and/or interior bore or passage 19 of adapter 18, to establish communication between inlet port 11 and outlet 12. Sealing primarily occurs between seal 67 and the interior of such bore. Obviously, a source of pilot fluid would be provided having access to inlet ports 10 and 11, and the outlet port 12 would be connected to actuator means for opening or closing a valve in the controlled conduit. Such pilot source and actuator structure is known as the art, and forms no part of this invention. As the slide valve is moved, including enlarged portion 75, from the position of FIG. 5 toward that of FIG. 3, there is an in termediate position, indicated by FIG. 4, wherein access from either inlet port to the outlet port is blocked. Thus, the arrangement shown herein is called center position closed" as distinguished from center position open, i.e., there can be no communication between the outlet port and either inlet port when the other inlet port is in communication with the outlet port. When the valve progresses to the position of FIG. 3, seal 68 is engaged with its counterpart taper 70a and/or bore 23 of adapter 22. Again, primary sealing occurs between such seal 68 and bore 23, the taper serving as a guide to entry of said seal into said bore. Notice that in movement, neither of seals 67 or 68 move across either inlet or outlet ports, thus greatly reducing damage to such seals. Further note that the maximum travel of valve 25 is very short distance, defined by the longitudinal separation between shoulders 70 of members 18 and 22 less the longitudinal dimension of enlarged portion 75. In applicants device, such movement is on the order of 0.050 of 1 inch. Considering the fact that applicants device is center position closed," flow of pilot fluid only begins to occur only during the last 0.0l0 inch of travel. Such extremely short travel reduces friction losses. Notice also, that the amount of travel is limited by the contact of enlarged portion with shoulders 70 of adapters 18 and 22. Not only do these members so limit travel, but also form a metal-tometal seal at the end of each stroke. Friction is further reduced by the provision of only 2 conventional seals, members 67, 68 moving with the slide valve. The remaining sliding contact between said slide valve and the interior bores occurs between the bores and the low friction bearings (Teflon type) and between the stem of member 27 and the balls.

At this point, it should be reitterated that the presence of such extended stem and ball bearing tends to overcome one common problem of spring-return assemblies, namely that caused by spring cocking or buckling, a further source of friction losses, and averts wear.

When the device of this invention is to be employed as a low pressure control, the compression in spring 35 is so set. That is, when the pressure within the controlled conduit, communicated through passage 38 to act on valve 25 and spring 35, falls below a predetermined minimum, the force exerted by spring 35 will move slide valve 25 downwardly, from the position of FIGS. 1 and 3, toward that of FIG. 5. When such valve movement occurs, seal 67 encounters taper 70a of adapter 18, and partially enters bore 19, closing off flow of pilot fluid between inlet port 11 and outlet port 12, also the lower shoulder of enlargement 75 seals against shoulder 70 of adapter I8. During the last ap' proximate 0010 inch of such movement. seal 68 disengages from taper 70a of adapter 22 to open communi cation between outlet port 12 and inlet port 10, for the bleeding of pilot fluid. In some types of actuators, such bleeding may cause a motor valve, not shown, to cut off fluid flow in the controlled conduit. Note, again, that no such bleeding may occur during the intermediate position (FIG. 4) due to this invention being center positioned closed."

Similarly, when the device of the present invention is to be employed as a high pressure cutoff device, the spring 35 will be adjusted accordingly, by virtue of the threaded connection between housing body 7 and cap 32, to increase the force acting on valve 25. This will cause seal 67 to be initially engaged with bore 19 of adapter 18 as in FIG. 5. At such time seal 68 will be disengaged from its taper 70a. During such time, pilot fluid may flow through inlet to outlet port 12 to maintain a motor valve (not shown) open and permit flow through the controlled conduit that communicates through passage 38. When pressure within such controlled conduit increases above a predetermined maximum pressure, it will force valve 25 against the force of spring 35, move seal 68 first against its associated taper 70a and close communication between inlet port I0 and outlet 12, and then on into bore 23 of adapter 22. When such movement passes the intermediate position of FIG. 4, bleeding of pilot fluid from outlet port 12 through inlet port 11 may occur, to cause closing of the controlled conduit.

It can be appreciated that the diameter of member 29 may be varied so as to increase the area exposed to controlled conduit pressure. This is illustrated in FIG. 2. It will be noted that this figure shows one end of valve body 7 in slightly modified form from FIG. 1. The valve body 7 includes again the longitudinally extending counterbore 9a, and a modified form 81 of valve plunger member 29. Plunger portion 81 is positioned in a further counterbore 82 off 9a, which counterbore 82 receives bearing housing 84, in which is carried movable bearing means 85. Annular follower 86 is sup ported by bearing means 85 and has connected thereto, such as by pin 87, a rod 88, which rod abuts the end of valve portion 28. Passage 38 communicates, through plug 90, between the controlled conduit and the enlarged diameter plunger 81. Suitable seal means 94 are provided to inhibit comingling of conduit fluid with pilot fluid. O-ring seal 95 is provided to inhibit fluid leakage.

Connected to rod 88 is extension 99 which extends outwardly of housing 6 and is provided with gripping member 100 so that it may be manually engaged to permit manual overriding, or valve actuation in the event of loss of pilot control power. Suitable seal means 101 surround extension 99 to inhibit leakage.

The operation of the form of the invention of FIG. 2 is like that previously described, except that a larger diameter plunger is provided, and a manually engageable feature is added.

Note that plunger 29 and adapter 16 of FIG. 1 may be interchanged with like members of varying diameters, i.e., for low pressure operation, plunger 29 would have its diameter increased, reducing the wall thickness of adapter 16. A nipple portion would act against member 25, since the remainder of the device above members 16 and 29 would not be changed. For high pressure operation, the arrangement shown would be appropriate.

Although limited embodiments have been described, it should be obvious that numerous modifications would be possible, by one skilled in the art, without departing from the spirit of the invention, the scope of which is limited only by the following claims:

I claim:

I. A device for controlling the flow of fluid in response to pressure variations in a controlled member, said device comprising:

a valve body having an axial bore therethrough;

said valve body having first and second inlet ports and an outlet port all communicating between said bore and exterior of said body; cylindrical hollow adapter means positioned in said bore, said adapter means having lateral passages therethrough communicating between both of said inlet ports and the interior of said adapter means;

slide valve means positioned within the interior of said adapter means;

said slide valve means including a first pair of annular seal members positioned on opposite sides of said outlet port; conduit means for communicating between said adapter means interior and said controlled member whereby pressure from said controlled member may exert a force against said slide valve means;

resilient means for yieldably urging said slide valve means in the direction of said conduit means, and means for varying the force so urging said resilient means; combination means for selectively (a) opening fluid communication between said first inlet port and said outlet port while simultaneously blocking fluid communication between said second inlet port and said outlet port deemed a first position, (b) opening fluid communication between said second inlet port and said outlet port while simultaneously blocking fluid communication between said first inlet port and said outlet port, deemed a second position, and (c) blocking communication between both of said inlet ports and said outlet port, deemed a third position; and

said combination means including the following;

a radially enlarged annular portion of said slide valve means having oppositely facing shoulders,

oppositely facing shoulders provided said adapter means abuttable with said slide valve shoulders, and

the axial separation of said slide valve shoulders is sufficiently less than the axial separation of said adapter shoulders such that on one of said slide valve shoulders abutting an adjacent one of said adapter shoulders said first position is assumed, and on the other of said slide valve shoulders abutting the other of said adapter shoulders said second position is assumed.

2. The device of claim 1 wherein said slide valve means includes, near one end, a stem portion, supported within said bore by low coefficient of friction ball bearing means.

3. The device of claim 2 wherein, other than said first pair of seal members, all contact between said slide means extending from said slide valve means outwardly of said body whereby said slide valve means may be manually actuated.

valve and either of said bore and the interior wall of said adapter means occurs through intermediate low coefficient of friction bearing means.

4. The device of claim 1 wherein the difference be tween said axial separation of said slide valve shoulders 5 and said adapter shoulders, and thereby, the maximum longitudinal movement of said slide valve, is approximately 0.050 inch.

5. The device of claim 1 and including projection 6. A device for controlling the flow of fluid in response to pressure variations in a controlled member. said device comprising:

a. a valve housing, said housing having a longitudinal bore therethrough;

b. valve means movable within said bore;

c. first and second inlet port means and outlet port means, each in communication with the exterior of said housing and said valve means;

d. conduit means in pressure communication be tween said controlled member and the interior of said housing, and thereby with said valve means;

e. resilient biasing means for adjustably exerting a force against said valve means tending to move it in the direction of said conduit means;

f. means for restricting axial movement of said valve means and prohibiting passage of any valve means seal from passing a lateral opening, said restricting means including first and second shoulders formed centrally of said valve means, and first and second blocking means, interior of said housing;

g. first and second annular seal means provided said valve means adjacent each of said shoulders; and 35 h. combination means for 1. opening communication between said first inlet port means and said outlet port means when said second shoulder abuts said second blocking means, while simultaneously blocking communication between said second inlet port means and said outlet port means, and for 2. sealingly blocking communication between said first inlet port means and said outlet port means when said first shoulder abuts said first blocking means while simultaneously opening communication between said second inlet port means and said outlet port means, and for 3. preventing simultaneous communication between both of said inlet port means and said outlet port means.

7. The device of claim 6 wherein the relative axial dimensions of a. the separation between said first and second shoulders, and (b) the separation between said first and second blocking means, is such that the maximum permitted travel of said valve means is approxi mately 0.050 inch.

8. The device of claim 7 wherein each of said first and second seal means are so positioned as to be sealingly disengaged during only approximately .010 inch of said permitted travel.

9. The device of claim 6 and including additional annular seal means provided said valve means, all such additional seal means and said ball bearing means being of such construction as to provide low coefficient of friction contact between said valve means and any ob ject radically exterior thereof. 

1. A device for controlling the flow of fluid in response to pressure variations in a controlled member, said device comprising: a valve body having an axial bore therethrough; said valve body having first and second inlet ports and an outlet port all communicating between said bore and exterior of said body; cylindrical hollow adapter means positioned in said bore, said adapter means having lateral passages therethrough communicating between both of said inlet ports and the interior of said adapter means; slide valve means positioned within the interior of said adapter means; said slide valve means including a first pair of annular seal members positioned on opposite sides of said outlet port; conduit means for communicating between said adapter means interior and said controlled member whereby pressure from said controlled member may exert a force against said slide valvE means; resilient means for yieldably urging said slide valve means in the direction of said conduit means, and means for varying the force so urging said resilient means; combination means for selectively (a) opening fluid communication between said first inlet port and said outlet port while simultaneously blocking fluid communication between said second inlet port and said outlet port deemed a first position, (b) opening fluid communication between said second inlet port and said outlet port while simultaneously blocking fluid communication between said first inlet port and said outlet port, deemed a second position, and (c) blocking communication between both of said inlet ports and said outlet port, deemed a third position; and said combination means including the following; a radially enlarged annular portion of said slide valve means having oppositely facing shoulders, oppositely facing shoulders provided said adapter means abuttable with said slide valve shoulders, and the axial separation of said slide valve shoulders is sufficiently less than the axial separation of said adapter shoulders such that on one of said slide valve shoulders abutting an adjacent one of said adapter shoulders said first position is assumed, and on the other of said slide valve shoulders abutting the other of said adapter shoulders said second position is assumed.
 2. The device of claim 1 wherein said slide valve means includes, near one end, a stem portion, supported within said bore by low coefficient of friction ball bearing means.
 2. sealingly blocking communication between said first inlet port means and said outlet port means when said first shoulder abuts said first blocking means while simultaneously opening communication between said second inlet port means and said outlet port means, and for
 3. The device of claim 2 wherein, other than said first pair of seal members, all contact between said slide valve and either of said bore and the interior wall of said adapter means occurs through intermediate low coefficient of friction bearing means.
 3. preventing simultaneous communication between both of said inlet port means and said outlet port meaNs.
 4. The device of claim 1 wherein the difference between said axial separation of said slide valve shoulders and said adapter shoulders, and thereby, the maximum longitudinal movement of said slide valve, is approximately 0.050 inch.
 5. The device of claim 1 and including projection means extending from said slide valve means outwardly of said body whereby said slide valve means may be manually actuated.
 6. A device for controlling the flow of fluid in response to pressure variations in a controlled member, said device comprising: a. a valve housing, said housing having a longitudinal bore therethrough; b. valve means movable within said bore; c. first and second inlet port means and outlet port means, each in communication with the exterior of said housing and said valve means; d. conduit means in pressure communication between said controlled member and the interior of said housing, and thereby with said valve means; e. resilient biasing means for adjustably exerting a force against said valve means tending to move it in the direction of said conduit means; f. means for restricting axial movement of said valve means and prohibiting passage of any valve means seal from passing a lateral opening, said restricting means including first and second shoulders formed centrally of said valve means, and first and second blocking means, interior of said housing; g. first and second annular seal means provided said valve means adjacent each of said shoulders; and h. combination means for
 7. The device of claim 6 wherein the relative axial dimensions of a. the separation between said first and second shoulders, and (b) the separation between said first and second blocking means, is such that the maximum permitted travel of said valve means is approximately 0.050 inch.
 8. The device of claim 7 wherein each of said first and second seal means are so positioned as to be sealingly disengaged during only approximately .010 inch of said permitted travel.
 9. The device of claim 6 and including additional annular seal means provided said valve means, all such additional seal means and said ball bearing means being of such construction as to provide low coefficient of friction contact between said valve means and any object radically exterior thereof. 